Move more shulker box checks in mcl_hoppers to mcl_util

mods/CORE/mcl_util/init.lua

@@ -127,6 +127,34 @@ function mcl_util.get_double_container_neighbor_pos(pos, param2, side)
 	end
 end
 
+-- Iterates through all items in the given inventory and
+-- returns the slot of the first item which matches a condition.
+-- Returns nil if no item was found.
+--- source_inventory: Inventory to take the item from
+--- source_list: List name of the source inventory from which to take the item
+--- destination_inventory: Put item into this inventory
+--- destination_list: List name of the destination inventory to which to put the item into
+--- condition: Function which takes an itemstack and returns true if it matches the desired item condition.
+---            If set to nil, the slot of the first item stack will be taken unconditionally.
+-- dst_inventory and dst_list can also be nil if condition is nil.
+function mcl_util.get_eligible_transfer_item_slot(src_inventory, src_list, dst_inventory, dst_list, condition)
+	local size = src_inventory:get_size(src_list)
+	local stack
+	for i=1, size do
+		stack = src_inventory:get_stack(src_list, i)
+		if not stack:is_empty() and (condition == nil or condition(stack, src_inventory, src_list, dst_inventory, dst_list)) then
+			return i
+		end
+	end
+	return nil
+end
+
+-- Returns true if given itemstack is a shulker box
+local is_not_shulker_box = function(itemstack)
+	local g = minetest.get_item_group(itemstack:get_name(), "shulker_box")
+	return g == 0 or g == nil
+end
+
 -- Moves a single item from one inventory to another.
 --- source_inventory: Inventory to take the item from
 --- source_list: List name of the source inventory from which to take the item
@@ -165,7 +193,7 @@ end
 --- source_pos: Position ({x,y,z}) of the node to take the item from
 --- destination_pos: Position ({x,y,z}) of the node to put the item into
 --- source_list (optional): List name of the source inventory from which to take the item. Default is normally "main"; "dst" for furnace
---- source_stack_id (optional): The inventory position ID of the source inventory to take the item from (-1 for first occupied slot; -1 is default)
+--- source_stack_id (optional): The inventory position ID of the source inventory to take the item from (-1 for slot of the first valid item; -1 is default)
 --- destination_list (optional): List name of the destination inventory. Default is normally "main"; "src" for furnace
 -- Returns true on success and false on failure.
 function mcl_util.move_item_container(source_pos, destination_pos, source_list, source_stack_id, destination_list)
@@ -210,11 +238,17 @@ function mcl_util.move_item_container(source_pos, destination_pos, source_list,
 		end
 	end
 
+	-- Automatically select stack ID if set to automatic
 	if not source_stack_id then
 		source_stack_id = -1
 	end
 	if source_stack_id == -1 then
-		source_stack_id = mcl_util.get_first_occupied_inventory_slot(sinv, source_list)
+		local cond = nil
+		-- Prevent shulker box inception
+		if dctype == 3 then
+			cond = is_not_shulker_box
+		end
+		source_stack_id = mcl_util.get_eligible_transfer_item_slot(sinv, source_list, dinv, destination_list, cond)
 		if source_stack_id == nil then
 			return false
 		end
@@ -268,13 +302,7 @@ end
 -- Returns the ID of the first non-empty slot in the given inventory list
 -- or nil, if inventory is empty.
 function mcl_util.get_first_occupied_inventory_slot(inventory, listname)
-	for i=1, inventory:get_size(listname) do
+	return mcl_util.get_eligible_transfer_item_slot(inventory, listname)
-		local stack = inventory:get_stack(listname, i)
-		if not stack:is_empty() then
-			return i
-		end
-	end
-	return nil
 end
 
 -- Returns true if item (itemstring or ItemStack) can be used as a furnace fuel.

mods/ITEMS/mcl_hoppers/init.lua

@@ -235,26 +235,6 @@ minetest.register_abm({
 	end,
 })
 
--- Iterates through all items in the given inventory and
--- return the slot of the first item which matches a condition
-local get_eligible_transfer_item = function(src_inventory, src_list, dst_inventory, dst_list, condition)
-	local size = src_inventory:get_size(src_list)
-	local stack
-	for i=1, size do
-		stack = src_inventory:get_stack(src_list, i)
-		if not stack:is_empty() and condition(stack, src_inventory, src_list, dst_inventory, dst_list) then
-			return i
-		end
-	end
-	return nil
-end
-
--- Returns true if given itemstack is a shulker box
-local is_not_shulker_box = function(itemstack)
-	local g = minetest.get_item_group(itemstack:get_name(), "shulker_box")
-	return g == 0 or g == nil
-end
-
 -- Returns true if itemstack is fuel, but not for lava bucket if destination already has one
 local is_transferrable_fuel = function(itemstack, src_inventory, src_list, dst_inventory, dst_list)
 	if mcl_util.is_fuel(itemstack) then
@@ -299,16 +279,7 @@ minetest.register_abm({
 		local downnode = minetest.get_node(downpos)
 		if not minetest.registered_nodes[downnode.name] then return end
 		g = minetest.registered_nodes[downnode.name].groups.container
-		local slot_id = -1
+		mcl_util.move_item_container(pos, downpos)
-		if g == 3 then
-			-- For shulker boxes, only select non-shulker boxes
-			local sinv = minetest.get_inventory({type="node", pos = pos})
-			local dinv = minetest.get_inventory({type="node", pos = downpos})
-			slot_id = get_eligible_transfer_item(sinv, "main", dinv, "main", is_not_shulker_box)
-		end
-		if slot_id then
-			mcl_util.move_item_container(pos, downpos, nil, slot_id)
-		end
 	end,
 })
 
@@ -344,21 +315,13 @@ minetest.register_abm({
 
 		-- Move an item from the hopper into the container to which the hopper points to
 		local g = minetest.registered_nodes[frontnode.name].groups.container
-		if g == 2 or g == 5 or g == 6 then
+		if g == 2 or g == 3 or g == 5 or g == 6 then
 			mcl_util.move_item_container(pos, front)
-		elseif g == 3 then
-			-- Put non-shulker boxes into shulker box
-			local sinv = minetest.get_inventory({type="node", pos = pos})
-			local dinv = minetest.get_inventory({type="node", pos = front})
-			local slot_id = get_eligible_transfer_item(sinv, "main", dinv, "main", is_not_shulker_box)
-			if slot_id then
-				mcl_util.move_item_container(pos, front, nil, slot_id)
-			end
 		elseif g == 4 then
 			-- Put fuel into fuel slot
 			local sinv = minetest.get_inventory({type="node", pos = pos})
 			local dinv = minetest.get_inventory({type="node", pos = front})
-			local slot_id, stack = get_eligible_transfer_item(sinv, "main", dinv, "fuel", is_transferrable_fuel)
+			local slot_id, stack = mcl_util.get_eligible_transfer_item_slot(sinv, "main", dinv, "fuel", is_transferrable_fuel)
 			if slot_id then
 				mcl_util.move_item_container(pos, front, nil, slot_id, "fuel")
 			end